1. Field of the Invention
This invention relates to the storage of bitmap font data within data processing systems.
2. Description of the Prior Art
Within data processing systems text data is typically stored as a sequence of character codes. When it is desired to present the text data to a user, for example by displaying it on a screen or printing it, then it is necessary to convert each character code into a graphical form that can be presented to a user. This conversion uses font data that specifies a graphical form for each character code. One type of font data is that in which a bitmap representation of the character is stored for each character code. Such bitmaps can be relatively simply processed for display or printing.
A problem that arises in such systems is the amount of storage capacity utilised in storing the font data and any associated data for accessing that font data. The amount of memory resource consumed can be a particular problem in the case of pictograph characters (such as Chinese, Korean and Japanese characters) where the number of characters that need to be represented can be very high, e.g. a Chinese pictograph font may include 13,000 different pictograph characters.
Measures that can reduce the amount of storage capacity needed to deal with font data are strongly desirable.